DE1301063B - Process for the production of vulcanizates containing fillers with high notch toughness - Google Patents

Description

1 2

The processing of rubber compounds with unsaturated carboxylic acids or their Andes The machines commonly used for this purpose are in particular hydride or, on the other hand, by grafting butabene high-cis-polybutadienes are still made of diene polymer, a number of unsolved problems. The implementation of the starting components themselves

The difficulties involved are mainly due to a lack of intrinsic tackiness, to polymerization, with up to a level of 1 to the inadequate manufacturing tackiness of the filler- 10 carboxyl groups per 100 chain carbon atoms, as well as crude rubber containing mixed substances is polymerized in the un- (depending on the initial ratio Bugünstige mixture plasticity and the associated _t tadien to unsaturated acid). The molecular weight can be attributed to insufficient sprayability. io of the copolymers obtained in this way is between 20,000 and 500,000.

of cis-1,4-polybutadiene with natural rubber or the carboxyl groups introduced in this way

Butadiene-styrene rubber in more efficient and use- finally neutralized by alkaline media. as process. In doing so, however, the alkaline media come preferably alkali possibility, the extreme advantages of high cis or alkaline earth metal hydroxides, carbonates and full use of polybutadiene containing, strongly single-oxides, besides also the corresponding connections are narrowed. To achieve an improvement here, it seems to be possible to fertilize the aluminum and zinc, therefore urgently desired. The neutralization can e.g. B. in the way

In addition, as is known, especially soot consequences show that the solution of the copolymer in one Filled vulcanizates of cis-1,4-polybutadiene do not use an organic solvent for a longer period of time sufficient resistance to further stirring with an aqueous solution of a metal powder under conditions of use by mechanical hydroxides, preferably alkaline earth hydroxides or chemical influences occurring cracks. delt and is then precipitated by methanol. On this inadequate, as tear strength or on the other hand, the common precipitation of the Notch toughness properties are those in 25 aqueous emulsion of the copolymer with the in strong measure in motor vehicle, especially truck tires from water dissolved stoichiometric amount of a Polybutadiene back-breaking tunnels - metal hydroxide possible. After all, it is often enough respectively. There is also an urgent need for new decay - even the homogeneous distribution of the alkaline wise to remedy this as well. Medium, which in this case is not necessarily water-

It has now been found that filler-containing 30 must be soluble in the solution or emulsion of the Vulcanized products with high notch toughness based on poly copolymers. Since the salt formation only takes place in the butadiene, copolymers of butadiene or the course of the subsequent customary operations. Polybutadiene-containing blends under Aus In this context is also to the

circuit of the disadvantages set out can be made, possibility to refer to the alkaline wherein the polymer or the blend 35 compound of the rubber mixture on the roller 1 to 30 percent by weight, preferably 2 to 15 percent by weight or can be added in a kneader, percent by weight, of a copolymer made from butadiene.

or isoprene and an unsaturated carboxylic acid borrowed processing steps are not thereby with 3 to 10 carbon atoms is added and the one thus obtained is influenced. The addition of the described mixed poly mixture vulcanized in a known manner, if a 40 can merisate before the processing of the polybutasolches Copolymer is used, which is based on diene rubber for solution or emulsion or 100 chain carbon atoms 1 to 20, for the most part also later by adding on the roller or in the contains neutralized carboxyl groups. Mixer done.

As polybutadienes, their processing and VuI- The amounts to be added of these mixed poly-

canisate properties improved according to the invention 45 merisates are 1 to 30 percent by weight, come primarily high-cis content, preferably 2 to 15 percent by weight, based on the Polybutadienes with proportions of the cis-1,4 configuration provided raw rubber. Furthermore from Z. B. 30 to 100% in question; in addition, these mixtures can be 2 to 100 parts by weight, the butadiene produced by other processes, preferably 5 to 50 parts of extending oil, based on polymers, ζ. B. their copolymers with styrene, 50 the polybutadiene rubber used, added as well as synthetic and natural polyisoprenes. Become there without affecting the advantageous properties of the in the case of it is irrelevant whether these are significantly impaired after the emulsion vulcanizate. Included process or by solution polymerization in it can be paraffinic, naphthenic or Presence of alkali metals, organometallic aromatic oils act.

Compounds or redox systems produced 55 The carbon black content can be 30 to 120, preferably 40 who are. up to 70 parts by weight, based on the amount used

In the same way, cuttings can also be made of rubber. In addition, fillers are to be used. of this kind can be used under the same conditions.

In particular, mixtures of poly- The vulcanization of the mixtures described come here

butadienes with butadiene-styrene rubber types 60 are carried out in the usual way. All of them are there (It does not matter whether these are with redox systems or with sulfur accelerator systems without restriction organometallic compounds in solution can be used for production, with their proportions being used were), but are mainly available with natural rubber, th rubber and copolymer, as well as with synthetic polyisoprenes in question. In addition, other vulcanization technologies

The mixtures to be used according to the invention, such as crosslinking with peroxides or the resin polymers from butadiene and an unsaturated vulcanization, in a known manner with the same Er carboxylic acid with 3 to 10 carbon atoms can be used once, by copolymerization of butadiene or isoprene.

especially with pure high-cis-content polybutadiene and with blends, in which it is contained in high proportions, has a considerably increased notch toughness. Already at Addition of 2 to 5 percent by weight of the copolymers to be used according to the invention are the Values increased significantly; when 10 parts are added, increases in value of more than 100% are observed. All other properties, including elasticity, experience only minor changes.

In addition to the plasticity improvement of the raw mixture with all processes influenced by it, which generally means processability by rolling, kneading, calendering, spraying, the positive in particular occurs with increasing dosage of the copolymers according to the invention Influence on the sprayability becomes more and more evident. This is how the polybutadienes Flow processes are significantly favored. This results in a more uniform shape of the molded part with a smoother one Surface. The plasticities of such mixtures are always considerably lower than those of the comparison samples; H. of the polybutadiene mixtures without additives such copolymers. The improvement of the manufacturing tack can also be achieved by simple Make hand test clear.

The vulcanizates produced in this way can be used with advantage in the tire sector, especially for truck tires, as well as in the manufacture of other rubber articles where high notch toughness is desired is to apply.

example 1

τ

4670 g of xylene, 1800 g of butadiene, 200 g of acrylic acid, 20 g of tert-dodecyl mercaptan and 10 g of di-tert-butyl peroxide were subjected to at 12O ⁰ C and a reaction time of 50 hours a controlled free-radical copolymerization.

The xylene solution of the copolymers was added with a necessary for the neutralization of the carboxyl stoichiometric amount of barium hydroxide and stirred for 5 hours at 50 ⁰ C vigorously. The resulting emulsion was precipitated with methanol and the polymer containing alkaline earths was dried in a vacuum drying cabinet.

II. Preparation of the rubber mixture

Recipe

Parts by weight
cis polybutadiene 100.00

(Copolymer according to I) variable amounts

according to table

Highly abrasion-resistant furnace soot ... 50.00

Stearic acid 2.00

ZnO 3.00

Phenyl-yS-naphthylamine 1.00

Aromatic oil 8.00

Sulfur 2.00

N-Cyclohexyl-benzthiazylsulfenamide 0.75

Heating: 40 minutes at 143 ° C.

pressure
ver
formunj I rest Ü IO
T-I OO
TI OO
TI r-
TH rubbed
/ M 22 h / 75 ° O OO it _O i co UI) VO ■ η- co CO ι— «-4-> Ü
Q IO IO > o tiickpi
ilastizi I * μ-ι Γ) ^ j. co CS O rte IO IO IO IO : a
K CS CS T-I TH U ?
O vo VO VO vo O IU O VO Γ OO 3Q Ί | x S. IO co ιο VO OO ON co O CS OO + J tn IO OO ON ; kei after
rrave kg / cm + rl- VO ON I. O ¹ - ' co
co IO Γ
ΟΟ ON
τ — Ι O co IO VO ON O "S3 ^§ £ T-I co VO ON module
300% G T-I T-I τ-Ι T-I O
ON Γ
ΟΟ O
OO β f
1 3 β IO CS CS ^ f- δ OO ON co co co • s • a OQ
CO IO co O IO r «
fa co
TI co
TI co
TI τ — Ι A ¹ S 'C M O T-I VO T-I Ag T- ^ CS ₁ CO ^ ^, >. ^: 3 »-Γ T-T T-T T-I 1 81 O OO t- VO VO : e men
merisai ^s setzl
poly: iä
(B.
ΚΩ 'Hurry 'Hurry 'Hurry Io
Sl S. IO Ir ¹
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The effect of the considerable increase in the notch toughness of cis-l ^ -Polybutadiene Vulkanisaten with increasing dosage of the copolymers to be used according to the invention is given by way of example of three different test methods clearly expressed here without any significant impairment of the rest of the values.

Example 2

A copolymer of butadiene and cinnamic acid was prepared analogously to the information in Example 1. The rubber mixture was also produced as described in Example 1, only the sulfur dosage was increased to 2.5 parts by weight.

The results obtained are shown in Table 2.

Tabel

Amount added
Copolymer Mooney
viscosity strength strain module
300% Notch
to Pohle ability
after Graves (ML-4) (kg / cm2) CVo) (kg / cm2) (kg / cm) vKg / CmJ
■ »- ■ + Without addition 74 142 378 105 10 29 18 +5 parts 67 138 366 102 15th 38 52 + 10 parts 65 149 386 101 19th 61 64

Notch toughness
by means of
Crescent rehearsal
(kg / cm) Table 2 continued hardness
(° Shore) Back
Elast
CV
22 ⁰ C bulging
ity
O)
75 ⁰ C pressure
deformation
rest
22h / 75 ° C Amount added
Copolymer 26 31
57 50
61 60 Permanent
strain 61
62
62 55
52
51 56
54
53 29
20th
25th Without addition
+5 parts
+ 10TeUe VO VO OO

Claims (1)

Claim: 40 Process for the production of filler-containing vulcanizates of high notch toughness based on Polybutadiene, copolymers of butadiene or blends containing polybutadiene, wherein 1 to 30 percent by weight of a copolymer is added to the polymer or the blend from butadiene or isoprene and an unsaturated carboxylic acid with 3 to 10 carbon atoms added and vulcanized the mixture thus obtained in a known manner, characterized in that that such a copolymer is used which has 1 to 20 per 100 chain carbon atoms, contains mostly neutralized carboxyl groups.